Dr. Steven L. Suib, Director of UConn’s Institute of Materials Science (IMS), is working to mitigate the effects of greenhouse gasses caused by carbon dioxide (CO2) emissions through carbon capture and conversion. His work was recently highlighted in a UConn video. IMS News reached out to Dr. Suib to discuss the impacts of the his research.
Dr. Suib’s research is highlighted in this video produced for UConn Today
How does carbon dioxide (CO2) negatively impact the environment and why is the research you are conducting critical to mitigating the impacts of CO2?
CO2 is a product of combustion from gas burning vehicles, industrial plants, and other sources. Enhanced levels of CO2 are believed to be responsible for global warming and the unusual patterns of weather throughout the world in recent years. We are trying to find ways to trap and gather carbon dioxide and also to transform this into materials that are less hazardous and with practical uses.
You state that CO2 must be trapped (or captured) in order to be converted. What methodology or methodologies are used to capture CO2 emissions?
There have been many different methods suggested to capture CO2 including physical methods of trapping in porous materials as well as chemical reactions for storage.
Discovering methods of converting CO2 to harmless but useful products requires the introduction of a catalyst to convert the gas. You have conducted extensive and often-cited research in catalysis. How does this expertise aid in your research?
The bonds in CO2 are strong and this gas is quite stable. There are many different types of catalysts that we have made. Different reactions are often catalyzed by different catalysts. To find better catalysts they need to be synthesized. The heart of our research programs centers around synthesis of new materials. Unique new materials including catalysts may have different and beneficial properties that commercially available materials do not have.
When you use the term “harmless but useful” in describing products that can be derived from the conversion of CO2, what types of products are possible?
The objective of activating CO2 is to make products that are safe and that can be used in different applications such as new fuels, new chemical feedstocks, and others. These in turn can be used in applications involving sustainable energy, medicines and pharmaceuticals, and new conducting systems (semiconductors, superconductors, batteries, supercapacitors).
It seems we have reached a critical stage in the climate crisis with calls for more research and, above all, action to reduce greenhouse gases and their negative effects. How urgent is the research you and your students and colleagues are conducting to the mitigation of the climate crisis? How close is the research to producing measurable outcomes?
The field of capturing and activating CO2 is very active right now, with numerous groups around the world trying to solve problems that would allow CO2 to be eventually used in many different commercial processes. Our work involves a small set of potential materials for capture and activation of CO2. There are measurable improvements in capture and activation. The key will be to push this to the limit so practical processes can be used.
Professor Emeritus of Chemical and Biomolecular Engineering, Richard Parnas, has been working on solutions to the oily waste we humans produce on a daily basis. He has been on a journey to convert that waste into usable energy. This quest has led to the patent of proprietary technology and the formation of REA Resources Recovery Services, a company he co-founded. Along with his partners in the company and in partnership with UConn, Dr. Parnas set about to convert FOG (Fat, Oil, Grease) into biodiesel for the benefit of municipalities in the state.
In 2019, REA contracted with the City of Danbury to build a FOG to biodiesel processing facility at the city’s wastewater treatment plant. That project has entered the construction phase and Parnas, REA, and UConn are now looking forward to the day the facility converts its first oily waste into usable biodiesel. IMS News reached out to Dr. Parnas about his research, the Danbury project, and the future of wastewater management.
Dr. Richard Parnas
You have been researching and developing methods to convert FOG (Fat, Oil, Grease) into biodiesel fuel since 2006. When did you first become interested in biofuels and what about biodiesel, in particular, led you down your current path?
I’ve been interested in biofuels, and green processing and green materials in general, for many years before coming to UConn. One of the important motivations for joining UConn was to participate in the development of the green economy. An undergraduate helped get me started working on biodiesel in the summer of 2007 by simply requesting my help to set up a biodiesel synthesis reaction in a fume hood.
When you became Director of the Biofuel Consortium here at UConn, you moved the bar from six gallons of biofuel produced over the course of a year to over 50 gallons continual production daily less than three years later. When did you realize the scale at which you might be able to convert FOG into biodiesel? What were the obstacles you faced and how were they overcome?
We used the yellow grease from UConn cafeterias to make biodiesel at that time, and the scale of operations was determined by the yellow grease production rate from the cafeterias. As a Chemical Engineer, my goal is always to maximize the use of available raw materials, and waste as small a fraction of that raw material as possible. Shortly after we started the Biofuel Consortium, we polled the various food service establishments at UConn to determine the yellow grease availability, and found it to be over 100 gallons per week. We then designed, built and installed a 50 gallon batch system, and produced 2 or 3 of the 50 gallon batches each week.
There were a number of obstacles. Production at that scale is not a typical academic activity so we faced skepticism from the facilities folks that ran the fuel depot for the buses. They asked if our fuel would be any good and how we would prove it to them, so we had to set up testing capability. Our testing was developed and run by Prof. James Stuart, an analytical chemist. Prof. Stuart and I received a grant of over $600,000 dollars to set up a biodiesel fuel quality testing facility in the Center for Environmental Science and Engineering (CESE) to test our biodiesel and the biodiesel produced by private companies. We also faced skepticism from the UConn administration since we were operating at a much larger scale than is typical. Safety concerns are important when conducting such operations with students who are just learning how to handle chemicals.
REA Resource Recovery Systems, a company which you co-founded and worked in collaboration with UConn to patent exclusive technology, has entered Phase 4 of its planned development of a 5000 square foot facility in Danbury that will turn FOG into biofuel. How important is wastewater management for municipalities and what will be the benefits for the City of Danbury once the facility is online.
I joined my two partners, Al Barbarotta and Eric Metz, to found REA at the end of 2017. The UConn patents were already in place for a piece of core technology called a counterflow multi-phase reactor that plays a key role in both the chemical conversion and in the product purification. Prof. Nicholas Leadbeatter from Chemistry is a co-inventor with me on that reactor, along with two undergraduate students. Beginning in 2015, I started working with a very low grade feedstock called brown grease, which is much harder to process than the yellow grease we had been working with earlier. Every single wastewater treatment plant in the world has a brown grease management and disposal problem, and every municipality has a wastewater management problem. In much of the world, wastewater management is required by law and heavily regulated to ensure that effluent meets standards for discharge into rivers and oceans.
Here in CT, the brown grease problem was handled by DEEP many years ago by mandating that certain wastewater treatment plants in the state become FOG receiving stations. Brown grease is the component of FOG that causes all the problems. These FOG receiving stations were given a small set of choices as to how to dispose of the brown grease they received, such as by landfilling or incineration. All the choices cost money and vectored pollution into the air, the land, or the water.
Danbury was mandated to become a FOG receiving facility several years ago, and undertook a general plant upgrade project to build a FOG receiving facility and then dispose of the FOG using biodigesters. When that disposal pathway became too difficult due to high cost they sought alternatives. REA was ready at that time to provide the alternative of converting the brown grease into a salable product, biodiesel. This solution provides two benefits to Danbury, an environmentally excellent disposal method and a source of revenue. REA estimates that the revenue will offset the cost of the project in Danbury in about 7 years, and that the payback period will be significantly shorter in larger facilities.
It has been 15 years since you undertook this journey of making biodiesel a viable alternative energy source. How does it feel to see your years of work coming to fruition with the Danbury project?
It feels terrifying because we have not yet started up the Danbury plant. When we successfully start Danbury, the relief and satisfaction will be enormous. Until then, for the next few months, everyone associated with the project is working very hard to finish the installation.
Since retiring in 2020, you appear to be just as active in your pursuit of science. What continues to drive you and is there anything you miss now that you have retired?
I am driven by the desire to see this biodiesel project through to completion and by the desire to play some small role in mitigating the unfolding climate catastrophe. When I started at UConn I was surprised that the academic definition of project completion is a final report. As an engineer, that did not seem to be enough because most reports are ignored and forgotten. Sometimes I miss the teaching aspect of working at UConn, but I think I most miss the camaraderie of my colleagues, with whom I have much less time now than I used to.
Three new grants totaling $7.5 million from ARPA-E and the U.S. Department of Energy (DOE) are enabling UConn researchers to conduct ground-breaking work on some of the nation’s most pressing energy problems.
Advanced Research Projects Agency-Energy (ARPA-E) grants provide funding for the development of transformational technologies that provide new ways of generating, storing, and using energy.
Shrinking Substations for Green Energy Integration
Yang Cao, a professor in the School of Engineering, is working on a three-year ARPA-E project to create a new technology that will help stabilize the power grid and integrate renewable energy sources into the existing energy infrastructure.
Substations are sprawling networks of wires, towers, and transformers. Substations change the high voltage that comes directly from energy generation stations into low voltage that can safely be delivered to homes or businesses.
The century-old energy infrastructure in the United States is prone to power outages, especially during increasingly common severe weather.
This infrastructure is also poorly suited to renewable energy sources as they were designed for fossil fuels.
With something like wind or solar energy, the energy sources are spread out across a huge expanse rather than coming from a neatly packaged oil barrel. Solar panels or wind turbines also tend to be in remote areas far from major cities that have massive electrical needs. This means we need more efficient technologies that can link distributed energy generators to urban areas.
Cao will work with Virginia Tech on the project, titled Substation in a Cable for Adaptable, Low-cost Electrical Distribution (SCALED), to develop high-voltage cables to replace bulky substations.
“We need a more versatile and compact conversion and integration solution for distributed renewable energies,” Cao says. “This overall project is targeting that.”
Making something this compact will be highly advantageous as they can be placed almost anywhere, whereas current substations require a tremendous amount of open space.
The goal of the project is to greatly reduce the footprint of substation technologies without compromising its effectiveness.
“We could really have a very compact substation that helps to convert and integrate the distributed energy generation into a grid instead of having really large, bulky substations,” Cao says.
A Better Path for New Materials
Dr. J. Nathan Hohman
Nate Hohman, assistant professor of chemistry, is working on a new DOE grant to develop artificial intelligence (AI) tools to improve the synthesis of new materials.
While scientists are constantly innovating new materials for energy, biotechnology, and many other applications, currently, the best tool they have at their disposal for this process is trial and error.
“Engineering a new hypothetical material today requires guesswork at every step,” Hohman says. “We guess what compounds might crystallize into a structure that may have a property of interest, hope we get the material we expected, and pray it has the properties we imagined. This is inefficient, labor intensive, and has a low likelihood of success.”
Hohman will combine nano-crystallographic characterization with Euclidean neural networks to develop a better technique for real-time characterization of materials using a continuously variable model material system.
Crystal characterization allows scientists to see how the atoms that make up a molecule are arranged. This information is critical for designing new materials as this structure is what determines what the material can do.
Hohman recently found a way to study crystal structure using an X-ray beam. This allowed his team to capture a crystal’s single diffraction pattern and merged them into a data set they can use to determine the atomic structure. This speeds up the process of characterizing new materials from months or even years to just hours.
Euclidean neural networks are artificial neural networks inspired by the human brain. A set of artificial neurons transmits signals to other neurons in the system in order to classify objects. Hohman’s collaborator Tess Smidt at MIT developed Euclidean neural networks that can handle 3-D geometries, like those of molecules.
Hohman in collaboration with other synthetic materials scientists, computational crystallographers, and deep learning researchers will use these networks to train machine learning algorithms to predict new phases of materials. This will help eliminate guesswork from materials development.
Hohman will have the neural networks will help scientists design and generate novel atomic geometries with desirable properties based on what the scientists want the material to do.
Designing for High Heat
Dr. Julián Norato
Julián Norato, associate professor of mechanical engineering, is working on an ARPA-E grant to develop computational techniques to design highly efficient and compact heat exchangers.
Heat exchangers are mechanical devices that transfer heat from a hot to a cold fluid. They are found in everything from air conditioners to space heaters to chemical plants to airplanes.
The heat exchangers Norato’s group will focus on operate at temperatures above 1100 degrees Celsius (approximately 2000 degrees Fahrenheit). These high-temperature heat exchangers are used in many applications, including gas turbine engines, waste heat recovery and hydrogen production.
The grant will focus on plate-and-frame heat exchangers, which consist of stacks of plates bolted together to a frame. The hot and cold fluids flow between alternate plates. Each plate has a pattern of obstacles to the flow embossed on one side. This helps increase the amount of heat transferred from the hot fluid to the plates, and to the cold fluid flowing through the adjacent plates.
“The fluid is forced to go through the flow structures inside the plates,” Norato says. “Essentially, you’re putting obstacles to the fluid to force it to mix and spend more time going from the inlet to the outlet of the plate.”
What these obstacles look like will determine how efficient the heat transfer is. The computational techniques that Norato’s group will formulate will determine the optimal shape and pattern of these obstacles to maximize the heat transfer. At the same time, the design must ensure the pressure drop the fluid experiences as it flows through a plate is kept to a minimum, and that the plates can sustain the pressure the fluid exerts at the high operating temperatures.
The researchers are also interested in making the device as small and light as possible, which is especially important in aerospace applications that have space and weight restrictions.
The project will be conducted in collaboration with Altair Engineering, whose computational fluid dynamics software the researchers will use to simulate the heat transfer and the mechanical behavior of the heat exchanger.
Norato will also collaborate with researchers from Michigan State University, who have developed an additive manufacturing technique to efficiently 3D print the heat exchanger plates out of a metal alloy that can operate at high temperatures. They will 3D print the plate designs obtained by the computational techniques developed by Norato and test the performance and integrity of the heat exchanger in an experimental setup.
planned development of a 5000 square foot facility in Danbury that will turn FOG into biofuel. How important is wastewater management for municipalities and what will be the benefits for the City of Danbury once the facility is online.
